Reliability and validity of the child health questionnaire-child form (CHQ-CF87) in a Dutch adolescent population

Feasibility, reliability, and discriminative validity of the cross-culturally adapted Dutch version of the originally US child health questionnaire-child form (CHQ-CF87), an 87-item generic pediatric health-related quality of life instrument, were assessed. The success criterion in this first evaluation was the equivalence of psychometric properties of the adapted and the original CHQ. A total of 466 schoolchildren (9–17 years) were invited to complete the questionnaire in the classroom. Test–retest reliability was measured after 14 days in a subgroup (n = 71). Response was 96%. Four scales had ceiling effects (> 50%), as was reported in an Australian study. Cronbach -values were adequate (> 0.70), except for physical functioning (0.56). Test–retest correlations, not previously reported, were not statistically significant for two CHQ-scales, whereas average retest scores indicated better health for five scales (p < 0.01). The CHQ scales discriminated significantly (p < 0.01) between children without (n = 281) and children with two or more self-reported chronic diseases (n = 59). This is in correspondence with US and Australian reports. Conclusions: The current data support application of the Dutch CHQ-CF in predominantly healthy populations, e.g. in school settings. Given the limitations of this study and some less favorable results (score distributions, internal consistency; test–retest reliability), further evaluation of the CHQ-CF is recommended, preferably by analyses of item performance and scale validity in international data sets that include varied clinical subgroups.     

Preliminary evidence on the measurement properties of the Chinese version of the child health questionnaire,parent form (CHQ-PF50) and child form (CHQ-CF87)

The objective of this study was to evaluate the reliability and construct validity of the Chinese parent form (PF50) and child form (CF87) of the Child Health Questionnaire (CHQ). Methods: To assess the construct validity and reliability of the Chinese versions, we invited 1099 parents of healthy children and 816 school children to complete the Chinese CHQ-PF50 and CHQ-CF87, respectively. Results: Psychometric analysis on item convergent validity and discriminant validity showed ≥99% rates of success for all 10 scales in the CF87 and ≥94% for all but one scale in the PF50, the exception being general health scale (86%). We observed minimal floor effects for both questionnaires, but substantial ceiling effects for five scales in both the PF50 and CF87 (physical functioning, role-emotional/behavioral, role-physical, bodily pain and family activities). A substantially lower ceiling effect was observed for the physical scale and bodily pain in the CF87 (19% and 25%, respectively) relative to the PF50 (46% and 42%, respectively). The median alpha coefficient for CF87 and PF50 was 0.90 (range, 0.80–0.94) and 0.78 (range, 0.44–0.88), respectively. Conclusions:Our findings suggest that the Chinese CHQ-PF50 and CHQ-CF87 are robust and sufficiently reliable for group comparisons and perhaps also for use in other Chinese populations.     

The factorial structure of the Chronic Liver Disease Questionnaire (CLDQ)

Objective The Chronic Liver Disease Questionnaire (CLDQ) is a disease-specific instrument designed to assess health-related quality of life in patients with chronic liver disease. The aim of this paper is to present the psychometric properties of a German version of this questionnaire. A special focus is placed on the analysis of the CLDQ’s factorial structure. Methods Five hundred and twenty-four patients completed the CLDQ from May 1999 to October 2006. The results were subject to item analysis, reliability and validity assessments, and confirmatory and exploratory factor analysis. Results The distribution characteristics on the item and scale level were satisfactory. Internal consistency was good to excellent; retest reliability acceptable. Validity could be confirmed by characteristic subscale correlations with other quality-of-life scales. Confirmatory factor analysis could not sufficiently reproduce the original factor structure. Exploratory factor analysis suggested five out of six subscales of the original version and yielded a new subscale: “sleep.” Conclusion CLDQ’s reliability and validity have been confirmed. In addition, the demonstrated practical administration of the questionnaire suggests that it should serve as a routine quality of life assessment of patients with chronic liver disease.     

Measuring Psychological Consequences of Screening: Adaptation of the Psychological Consequences Questionnaire into Dutch

Objective: To assess the psychometric properties of a Dutch adaptation of an originally Australian instrument measuring the psychological impact of breast cancer screening. Methods: The three subscales (emotional, physical, social) of the Psychological Consequences Questionnaire (PCQ) underwent formal linguistic and cultural translation. A total of 524 women under intensive surveillance because of increased breast cancer risk were asked to complete the questionnaire at 2 months prior to screening, at the day of the screening visit preceding the screening, and 1–4 weeks after screening. Acceptability, score distribution, internal consistency, scale structure, responsiveness to change and construct validity were analysed. Results: Response rates were high (98–94%) and there were very few missing answers and non-unique answers. All scales had Cronbach’s αs > 0.70. The physical and social subscale showed ceiling effects. The item-own scale correlations were only slightly higher than the corresponding item-other scale correlations. Factor analysis showed that the assumed three separate subscales were replicated in our study. Pre- and post-screening effect sizes for the emotional scale were larger than for the other two scales. All PCQ scales correlated with the scales of two other psychological measures (p ≤ 0.01). The emotional scale and the total PCQ score were able to differentiate between subgroups varying in affective risk perception (p ≤ 0.01). Conclusion: The Dutch PCQ is useful in measuring psychological impact among women under intensive surveillance because of high breast cancer risk.     

Psychometric properties of the Korean version of the job content questionnaire: data from health care workers

Objectives To test the validity and reliability of selected scales, namely, decision latitude, psychological job demand, social support, job insecurity, and macro-level decision latitude from the Korean version of the job content questionnaire (K-JCQ), as part of a psychosocial epidemiological study among university hospital workers. Methods K-JCQ was developed by translation and back translation complying with the JCQ usage policy, and its psychometric properties were explored among 338 workers (290 females and 48 males) in a university hospital in Korea. Internal consistency was examined using Cronbach’s alpha correlation coefficients. Factorial validity was tested using exploratory factor analysis. Pearson’s correlation coefficients were used for test–retest reliability among a subset of 157 workers who responded to a repeat survey. Criterion-related validity was assessed by investigating the effects of the scales on job satisfaction and self-identity through work in multiple regression models. Results Cronbach’s alpha for all selected scales was higher than 0.6, except for job insecurity (0.53) and macro-level decision authority (0.52), indicating appropriate internal consistency. Correlation coefficients between test and retest scales of decision latitude, psychological job demand, and social support were 0.60, 0.41, and 0.35, respectively. Exploratory factor analysis found three- and four-factor models, i.e., with and without macro-level decision latitude, respectively, closely corresponding to the theoretical constructs. High levels of decision latitude and social support, and low levels of psychological job demand and job insecurity were significantly associated with high level of job satisfaction. Higher self-identity through work was positively related to decision latitude and social support. Conclusions These findings suggest that K-JCQ is valid and reliable for assessing psychosocial job stress among Korean workers. Macro-level decision latitude showed a separate factorial structure and was strongly associated with task-level decision latitude.     

Psychometric properties of the initial Brazilian version of the CHQ-PF50 applied to the caregivers of children and adolescents with cerebral palsy

Goals To evaluate the psychometric properties of the initial Brazilian version of the Child Health Questionnaire(CHQ-PF50) in children and adolescents with cerebral palsy(CP). Methods The caregivers of 5- to 18-year-old children and adolescents with CP answered the self-administered CHQ-PF50 questionnaire. Data quality, reliability and validity were studied. The Gross Motor Function Measure was used to assess physical function. Results Ninety-six caregivers answered the questionnaire. Patient age ranged from 5 to 17.9 years (mean: 9.3 years). Missing data rate was low. Floor effect occurred in 3 scales and was substantial for quadriplegia group (63.6–77.3%). Ceiling effect occurred in 9 scales. Reliability was adequate for all scales except for the general health perception scale (Cronbach alpha coefficient = 0.24). The validity was adequate in general, but the role/social limitations-emotional behavioral scale was not satisfactory for discriminant and divergent validity. Conclusion The initial Brazilian version of the CHQ-PF50 showed, in general, adequate psychometric properties for application in patients with CP. Although floor and ceiling effects are expected in heterogeneous group as a limitation inherent to generic assessment instruments, they must be carefully considered in further studies. The general health perception and role/social limitations-emotional behavioral scale must be further reviewed for this population.     

Psychometric evaluation of the Schizophrenia Quality of Life Scale (SQLS) in English- and Chinese-speaking Asians in Singapore

Objective To assess the psychometric properties of the Schizophrenia Quality of Life Scale (SQLS) in Asians with schizophrenia in Singapore. Methods A consecutive sample of outpatients with schizophrenia completed the English or Chinese version of the SQLS and the Short-Form 36 Health Survey (SF-36) twice during two different clinic visits. The patients were also assessed for presence or absence of 22 psychiatric symptoms. Results About 202 patients (English-speaking: 140) participated in the study. Correlations between SQLS scales and other measures assessing similar constructs ranged from 0.46 to 0.69 (P < 0.001 for all). For SQLS psychosocial and symptoms/side effects scales, item-to-scale correlations were >0.4, Cronbach’s alpha and intra-class correlation coefficient values were close to or exceed 0.7, and Cohen’s effect size, standardized response mean, and Guyatt’s responsiveness index values approximated or exceeded 0.2 for both SQLS language versions; however, for the energy/motivation scale, item-to-scale correlations (range: 0.08–0.51), reliability (range: 0.46–0.66) and responsiveness (range: 0.04–0.08) statistics were not satisfactory for both SQLS versions. Conclusions The SQLS psychosocial and symptoms/side effects scales are valid, reliable and responsive in Singaporean patients with schizophrenia; the appropriateness of energy/motivation scale requires further investigation.     

The ORTHO BC-SAT – a satisfaction questionnaire for women using hormonal contraceptives

Objective To assess the reliability and validity of the ORTHO Birth Control Satisfaction Assessment Tool (ORTHO BC-SAT). Design 339 women using 1 of 4 hormonal birth control methods (oral contraceptives, transdermal patch, vaginal ring, injections), completed the questionnaire 1–2 times. Materials and methods The questionnaire was developed based on findings from the literature, focus groups, and interviews. Internal consistency reliability, test–retest reliability, construct validity, and known groups validity were evaluated. Results Based on variable clustering, 8 domains were identified (Ease of Use/Convenience, Compliance, Lifestyle Impact, Symptom/Side Effect Bother, Menstrual Impact, Future Fertility Concerns, Assurance/Confidence, Overall Satisfaction). Internal consistency reliability was demonstrated with Cronbach’s α values ranging from 0.70 to 0.89. All multi-item scales reported acceptable test–retest reliability (0.79–0.87). Construct validity was demonstrated by support of a hypothesized pattern of correlations. Known groups validity was confirmed by examining scale scores of women categorized by levels of symptom bother. As expected, women with the least amount of bother reported higher scores on all satisfaction scales than those with higher bother (p < 0.0001), except on Future Fertility Concerns (p = 0.27). Conclusion Our results support the reliability and validity of the ORTHO BC-SAT. It may be used in future studies to evaluate satisfaction among hormonal contraceptive users.     

Measuring Clients’ Perception of Functional Limitations Using the Perceived Functioning &; Health Questionnaire

Background The Perceived Functioning & Health (PFH) questionnaire was developed to collect, in a standardized manner, which work activities are limited due to health conditions according to the perception of the client. In this study the questionnaire’s reliability and validity are investigated. Methods The PFH questionnaire is comprised of 147 questions, distributed over 33 scales, pertaining to the client’s psychosocial and physical work limitations. The PFH data of 800 respondents were analyzed: 254 healthy employees, 408 workers on sick leave and 138 recipients of a disability pension. Internal consistency (Cronbach’s α) for the scales was established. The test–retest reliability was examined for the data of 52 recipients of a disability pension who filled out the PFH twice within an interval of 1 month. Validation was established by taking the nature of the limitations as a criterion: mental limitations, physical limitations or a mix of both. To this end, the respondents were divided into groups distinguished on the basis of self-classification, as well as classification on the basis of disease codes given by insurance and occupational health physicians: a “healthy” group, subjects with only physical (“physical” group) or mental limitations (“mental” group) or mixed limitations (“mixed” group). The scale scores of these groups were compared and tested using analyses-of-variance and discriminant analyses. Results The scales were found to have sufficient to good internal consistency (mean Cronbach’s-α = 0.79) and test–retest reliability (mean correlation r = 0.76). Analyses-of-variance demonstrated significant differences between the scores of the mental, physical and healthy groups on most of the expected scales. These results were found both in groups defined by self-classification as well as in groups based on disease codes. Moreover, discriminant analyses revealed that the a priori classification of the respondents into three groups (mental, physical, healthy) for more than 75% of them corresponded with the classification on the basis of scale scores obtained from the questionnaire. Furthermore, limitations due to specific types of complaints (low back pain, fatigue, concentration problems) or diagnosed disorders (musculoskeletal disorders, reactive disorders, endogenous disorders) were clearly reflected in the scores of the related scales of the PFH. Conclusion The psychometric properties of the PFH with respect to reliability and validity were satisfactory. The PFH would appear to be an appropriate instrument for systematically measuring functional limitations in subjects on sick leave and in those receiving disability pensions, and could be used as a starting point in a disability claim procedure.     

Canadian-French, German and UK versions of the Child Health Questionnaire: methodology and preliminary item scaling results

Using emerging international guidelines, stringent procedures were used to develop and evaluate Canadian-French, German and UK translations/ adaptions of the 50 item, parent-completed Child Health Questionnaire (CHQ-PF50). Multitrait analysis was used to evaluate the convergent and discriminant validity of the hypothesized item sets across countries relative to the results obtained for a representative sample of children in the US. Cronbach's a coefficient was used to estimate the internal consistency reliability for each of the health scales. Floor and ceiling effects were also examined. Seventy-nine percent of all the item-scale correlations achieved acceptable internal consistency (0.40 or higher). The tests of the item convergent and discriminant validity were successful at least 87% of the time across all scales and countries. Equal item variance was observed 90% of the time across all countries. The reliability coefficients ranged from a low of 0.43 (parental time impact, Canadian English) to a high of 0.97 (physical functioning index, Canadian French) across all scales (median 0.80). Negligible floor effects were observed across countries. Noteworthy ceiling effects were observed, as expected, for the hypothesized physical scales (mean effect 73%). Conversely, fewer ceiling effects were observed for the psychosocial scales (range 3–17% behaviour parental emotional impact). The item-scaling results obtained in these pilot studies support the psychometric properties of the American-English CHQ-PF50 and its respective translations.     

Adaptation,Update and Validation of the General Nutrition Questionnaire in a Portuguese Adolescent Sample

This article describes the adaptation of the adult Portuguese version of the General Nutrition Knowledge Questionnaire (GNKQ) for adolescents, and its validation. Respondents were 1,315 adolescents, who completed the questionnaire in two phases. A subsample of 73 adolescents was used to measure test–retest reliability. Concurrent validity was tested using a sample of 32 dietetic students. The adapted version showed high internal consistency (Cronbach’s alpha = 0.92), test–retest reliability (R = 0.71) and concurrent validity (U = 22766.0; p < .01). Adolescents’ nutrition knowledge can now be assessed with a valid and reliable instrument. Future validation works of this or others questionnaires for children and elderly are warranted.     

The Use of Focus Groups in the Development of the KIDSCREEN HRQL Questionnaire

There is increasing interest in the public health sector in the health-related quality of life (HRQL) of healthy children. However, most HRQL instruments are developed for children with a chronic illness. In addition, existing questionnaires are mostly based on expert opinion about what constitutes HRQL and the opinions and views of healthy children are seldom included. In the European project KIDSCREEN, a generic questionnaire was developed for children between the ages of 8 and 18 on the basis of children’s opinions about what constitutes HRQL. Focus group discussions were organised in six European countries to explore the HRQL as perceived by children. There were six groups in each country, stratified by gender and age. The age groups were 8–9 years, 12–13 years, and 16–17 years, with 4–8 children in each group. Experienced moderators guided the discussions. The full discussions were audiotaped, transcribed and content-analysed. The discussions went smoothly, with much lively debate. For the youngest group, the most important aspect of their HRQL was family functioning. For both younger and older adolescents, social functioning, including the relationship with peers, was most important. Children in all groups considered physical and cognitive functioning to be less important than social functioning. These key findings were taken into account when designing the KIDSCREEN HRQL questionnaire for healthy children and adolescents, with more emphasis being placed on drawing up valid scales for family and social functioning. In addition, items were constructed using the language and lay-out preferred by the youngsters themselves. We conclude that focus groups are a useful way of exploring children’s views of HRQL, showing that an emphasis should be placed on constructing valid social and family scales.     

Reliability, validity and responsiveness of the German Short Musculoskeletal Function Assessment Questionnaire in patients undergoing surgical or conservative inpatient treatment

Objective: The patient-based evaluation of outcome is gaining increased importance. The aim of the study was to demonstrate the reliability, validity and responsiveness of the German version of the Short Musculoskeletal Function Assessment Questionnaire (SMFA-D) in patients undergoing surgical or conservative treatment. Methods: Three hundred and thirty-two patients suffering from osteoarthritis of the hip or knee, rheumatoid arthritis or rotator cuff tear undergoing surgical or medical inpatient treatment were followed up for 12 month. Patients underwent both SMFA-D and other assessments and clinical as well as radiological examinations. Reliability, validity and responsiveness of the SMFA-D were evaluated. Results: Values of the SMFA-D subscales, Function index (M 22–49, SD 12–20, range 0–96) and Bother index (M 29–52, SD 15–23, range 0–100), showed a normal distribution. Internal consistency (0.88–0.97) and retest reliability (0.71–0.96) coefficients were satisfactory to excellent. In most cases, the SMFA-D correlated significantly with function tests, physicians’ function ratings, patients’ pain ratings and other quality-of-life questionnaires in all patient subgroups. The results support both the construct and criterion validity of the measure. Different patient groups and subgroups could be discriminated with the SMFA-D scales. The standardized response means of SMFA-D subscales were in surgical patients better than in conservatively treated patients and comparable to those of the SF-36 Physical Component Summary scale. Conclusions: The German version of SMFA is a reliable, valid and responsive questionnaire in patients with osteoarthritis of the hip or knee, rheumatoid arthritis or rotator cuff tear undergoing surgical or medical inpatient treatment. Thus, the use of the SMFA-D in these patients can be recommended.     

Validity and Reliability of the Italian Version of the Quality of Life,Enjoyment and Satisfaction Questionnaire

The Quality of Life, Enjoyment and Satisfaction Questionnaire (Q-LES-Q) is increasingly used in psychiatry because it gives emphasis to the subjective perspective of patients on physical, psychological and social domains. This paper reports on the validation of the Italian version of the Q-LES-Q in a large multicenter study (EQUIP) conducted at five Italian sites on outpatients in treatment for anxiety disorders. Study participants underwent a broad assessment of psychopathology including the MINI-International Neuropsychiatric Interview, the Symptom Checklist (SCL-90) and the Clinical Global Impression (CGI). Cronbach’s alpha was used to determine the internal consistency of the Q-LES-Q areas and Pearson’s r was used to analyze the correlation between the areas of Q-LES-Q and those of the other instruments. The internal consistency of the Q-LES-Q proved to be substantial (>0.80 in each of the areas) as well as the test–retest reliability. The convergent validity of the Q-LES-Q vs. the Work and Social Adjustment Scale was examined. High correlations were found between scales measuring similar constructs in the two instruments and lower correlation between scales measuring different constructs. In conclusion, the Italian version of the Q-LES-Q proved to be as valid and reliable as the original English version.     

Parent and health professional perspectives in the management of adolescents with diabetes: Development of assessment instruments for international studies

Objective: Assessment of quality of life (QOL) in adolescents with diabetes requires patient, parent and health professional input. Psychometrically robust instruments to assess parent and professional perspectives are required. Research design and methods: Questionnaires concerning adolescent QOL were developed for completion by parents and health professionals. In an international study assessing QOL in 2,101 adolescents with diabetes (median age 14 years, range 10–18; from 17 countries including Europe, Japan and North America), parents and health professionals completed their respective questionnaires between March and August 1998. Results: Feasibility and acceptability of the new questionnaires were indicated by high questionnaire completion rates (adolescents 92%; parents 89%; health professionals 94%). Internal consistency was confirmed (Cronbach’s α coefficients 0.80 parent; 0.86 health professional). Correlations of Diabetes Quality of Life Questionnaire for Youths (DQOLY) scores with parent and health professional global QOL ratings were generally low (r ranging from 0.12 to 0.36). Parent-rated burden decreased incrementally across adolescence, particularly for girls. Professional-rated burden followed a similar profile but only after age 15 years. Until then, burden was rated as uniformly high. Clinically relevant discrepancies in parent and professional burden scores were noted for one-parent families and families where adolescents had been referred for psychological help. In both cases, health professionals but not one-parent families perceived these as high burden situations. The clinical significance of this relates to the significantly poorer metabolic control recorded for adolescents in both situations. Conclusions: Parent and health professional questionnaires were found to have adequate internal consistency, and convergent and discriminant validity in relation to key clinical and QOL outcomes. The questionnaires are brief, easy to administer and score. They may also enable comparisons across countries and languages to facilitate development of international health outcome parameters. The inclusion of the parent and health professional perspectives completes a comprehensive assessment of adolescent QOL relevant to diabetes.     

Pilot of a Child Health Electronic Surveillance System (CHESS) in Malta

Following a 6-year period of system design and planning, the Primary Health Care Department in Malta introduced a Child Health Electronic Surveillance System (CHESS) within Well Baby Clinics and primary schools. The primary aim was to computerize all activities of the child surveillance system to create an electronic health record which could eventually be linked to the child’s hospital, immunization and referral records. Data generated will be used to monitor the quality of the programme by identifying process and output indicators. Identified indicators included uptake of check-ups at different ages, number of defaulters, age at which check was carried out versus target age and outcome for components of check-ups. The aims of the pilot were to test the electronic system on site and monitor its performance in terms of the efficiency of data entry and quality of clinical data management. The possibility of collecting useful information on some of the identified 38 core child health indicators for Europe has been evaluated. A period of pilot testing was performed in one Well Baby Clinic. Prior to running the system, all users were trained and additional staff was appointed to take on responsibilities for maintenance and troubleshooting. Testing was performed during clinical appointments held from October 2006 to December 2006. Initial feedback from users was positive. They felt confident with the system and agreed that it improved efficiency and quality of the clinical information. Computer use during clinical sessions did not prolong encounter time. Backup systems were in place but were not activated. Parents have also commented positively on the use of the system as they were able to request a printout of their child’s clinical examination. Nurses felt that planning for scheduled clinics was easier as no paper records needed prior retrieving. Preliminary data showed that 42% of children aged 6–8 weeks were breastfed; most parents were not concerned about their preschool child’s growth or development. Physical abnormalities were identified in 7% and in 4.5% developmental abnormalities were detected. Growth data showed that 4% of preschoolers had weights above the 97th centile for age.     

Validity,reliability, and responsiveness of the Kansas City Cardiomyopathy Questionnaire in anemic heart failure patients

Background While generic health status measures quantify the impact of all patients’ diseases on their health-related quality of life, disease specific measures focus on only one of the many conditions that a patient may have. If a patient has two diseases with similar clinical manifestations, they may respond differently to a disease-specific instrument if one of their conditions improves while the other worsens or remains stable, thus undermining the instruments in that patient population. We sought empirical evidence of the reliability and validity (including responsiveness) of the Kansas City Cardiomyopathy Questionnaire (KCCQ), a disease-specific measure for heart failure (HF), among HF patients with and without anemia, a condition that has similar symptoms to HF. Methods This work used a prospective cohort study of 811 HF outpatients from 58 U.S. centers with a baseline assessment of anemia of whom 698 were followed for 3 months with serial health status measures. Results Among participants, 268 (33%) were anemic. The construct validity of the KCCQ was supported by showing similar correlations with the New York Heart Association (NYHA) classification in patients with and without anemia (P value for interaction = 0.38). The internal consistency (Cronbach’s alpha = 0.92 and 0.93 for anemic and non-anemic patients, respectively) and test–retest reliability (mean 3-month change scores in stable patients = −2.8 [SD = 1.4] and −0.5 [SD = 0.8], P = 0.14) were similar. Estimates of responsiveness were also similar. Conclusion This study provides empirical evidence that the psychometric properties of the KCCQ are similar in patients with or without anemia, a potentially confounding clinical condition in patients with heart failure.     

ISSQoL: A New Questionnaire for Evaluating the Quality of Life of People Living with HIV in the HAART Era*

Objective: To design a Health-related Quality of Life (HRQoL) instrument for HIV-infected people in the era of highly active antiretroviral therapy (HAART). Methods: The self-administered questionnaire was developed by an Italian network including researchers, physicians, people living with HIV, national institutions and community-based organizations (CBO) through several steps: (1) review of existing HRQoL literature and questionnaires for HIV-infected people; (2) selection of relevant domains measuring HRQoL in HIV-infected people, and identification of new domains related to new aspects of HRQoL concerning HAART-treated individuals; (3) conduction of two pre-test analyses in independent groups of Italian HIV-positive people (n≌100) distributed throughout the country. The objectives of the first pre-test were to verify the usefulness of the questionnaire, to construct a form easily understandable by everyone, to define the domains and their significance; the second pre-test aimed at evaluating and reshaping the questionnaire based on a statistical analysis of the outcomes of first pre-test; (4) validation analysis. A large cohort of people with HIV infection was recruited for the last step.Results: The internal consistence reliability (Cronbach’s α) was ≥0.70 for all domains. Most domains had Cronbach’s coefficient >0.80. All domains demonstrated convergent and discriminant validity. The final version of ISSQoL includes two sections: HRQoL Core Evaluation Form (9 domains) and Additional Important Areas for HRQoL (6 domains). The ISSQoL was administered together with two additional forms: a Daily Impact of Symptoms Form and a Demographic Information Form. The Additional Important Areas for HRQoL include social support, interaction with medical staff, treatment impact, body changes, life planning, and motherhood/fatherhood.Conclusion: The data reported in the present paper provide preliminary evidence of the reliability and validity of the ISSQoL questionnaire for the measurement of HRQoL in HIV-infected people. The direct involvement of HIV-positive people in all the phases of the project was a key aspect of our work. All the authors of this paper belong to ISSQoL Group.     

Psychometric properties of the Korean version of the effort–reward imbalance questionnaire: a study in a petrochemical company

Objective To evaluate the criterion validity, factorial validity, and internal consistency of Korean version of effort–reward imbalance (ERI) for the scales of effort, reward, and overcommitment as well as to examine the effect of psychosocial factors on physical and mental illness among petroleum refinery workers in South Korea. Methods The Korean version of ERI questionnaire was constructed using the translation and back-translation technique, and its psychometric properties were explored among 908 male workers in a large petroleum refinery in South Korea in 2002. Cronbach’s alpha coefficient was used to test internal consistency. An exploratory factor analysis was conducted on all items of the instrument. Confirmatory factor analyses were conducted on each dimension of effort, reward and overcommitment. Physical and mental health was measured by self-rated health (SF-8). The lowest tertiles of the scores were defined as illness. Multiple logistic regression models were used to test the effect of job stress on the physical and mental health (criterion validity of ERI scales). Results The Cronbach’s alpha coefficients for effort, reward, and overcommitment were 0.71, 0.86, and 0.75, respectively, indicating satisfactory internal consistency. Exploratory factor analysis found three latent factors, which closely corresponded to the theoretical structure of the ERI model. Acceptable construct validity was shown using confirmatory factor analysis. The highest tertile of effort–reward ratio was significantly associated with physical illness (OR 2.4, 95% CI 1.7–3.6) and mental illness (OR 2.9, 95% CI 2.0–4.2), compared to lower tertiles. Overcommitment was significantly associated with mental illness, but not with physical illness. Conclusions These findings contribute to the validity and reliability of the Korean ERI questionnaire. Importantly, in the context of a rapid change in the labour market, the lack of reciprocity between efforts and rewards at work is strongly associated with self-rated physical and mental health.     

Do the SF-36 and WHOQOL-BREF Measure the Same Constructs? Evidence from the Taiwan Population*

Background: The SF-36 and WHOQOL-BREF are available for international use, but it is not clear if they measure the same constructs. We compared the psychometric properties and factor structures of these two instruments. Methods: Data were collected from a national representative sample (n=11,440) in the 2001 Taiwan National Health Interview Survey, which included Taiwan versions of the SF-36 and WHOQOL-BREF. We used Cronbach’s alpha coefficient to estimate scale reliability. We conducted exploratory factor analysis to determine factor structure of the scales, and applied multitrait analysis to evaluate convergent and discriminant validity. We used standardized effect size to compare known-groups validity for health-related variables (including chronic conditions and health care utilization) and self-reported overall quality of life. Structural equation modeling was used to analyze relationships among the two SF-36 component scales (PCS and MCS) and the four WHOQOL subscales (physical, psychological, social relations, and environmental). Results: Cronbach’s alpha coefficients were acceptable (⩾0.7) for all subscales of both instruments. The factor analysis yielded two unique factors: one for the 8 SF-36 subscales and a second for the 4 WHOQOL subscales. Pearson correlations were weak (<0.3) among subscales of both instruments. Correlations for subscales hypothesized to measure similar constructs differed little from those measuring heterogeneous subscales. Effect sizes suggested greater discrimination by the SF-36 for health status and services utilization known groups, but greater discrimination by the WHOQOL for QOL-defined groups. Structural equation modeling suggested that the SF-36 PCS and MCS were weakly associated with WHOQOL. Conclusions: In this Taiwan population sample, the SF-36 and WHOQOL-BREF appear to measure different constructs: the SF-36 measures health-related QOL, while the WHOQOL-BREF measures global QOL. Clinicians and researchers should carefully define their research questions related to patient-reported outcomes before selecting which instrument to use. * Presented in part at (1) 11th Annual Conference of the International Society for Quality of Life Research. Hong Kong, China, 2004. (2) 2004 Quality of Life Symposium – Conceptualization and Measurement issues in QOL. Tai-Chuan, Taiwan, 2004